Context

         > @rootulp Could you elaborate on having an extra command for blobs? You mentioned filling up the blocks, but I didn't quite get that. Should it dynamically produce a PFB number, blob amount per PFB and blob sizes based on some network parameters and then spam the chain?

Yes. I want a way to more easily fill blocks to their max capacity. Currently Celestia blocks can contain 8 MiB of blob data but each individual blob is limited to ~2 MiB. This means that a user needs to submit 4 x ~2 MiB (or slightly smaller) blobs in order to fill a block. Even when I tried doing that via txsim, I wasn't able to consistently fill blocks so there may be other issues needed to accomplish my goal. You can skip this and/or extract it to a new issue so that it doesn't block the work in this PR.

Problem

It's difficult to actually fill blocks on a testnet. It would be nice if txsim had a command to fill blocks so that users don't have to fiddle with the flags --blob, --blob-amounts, --blob-sizes

Extends #4223 #4340 (comment)